All around Earth is a sea of gases called

the atmosphere. This is the air part ofEarth’s biosphere and the changeable of

Earth’s environments. This sea of gasesprotects people from harmful rays andmaterials from space and holds the airpeople need for life.

• Nitrogen and Oxygen – make up most of the atmosphere.

Nitrogen – 78 % nourishes plant lifeOxygen – 21 % needed by people to

breathe

* Other gases such as argon and carbon dioxide, make up the rest.

• The ATMOSPHERE is also the source of Earth’s weather and climate patterns.

• WEATHER is the condition of the atmosphere at a certain place at any one time.

• CLIMATE means the general kinds of weather a certain place has over a long time.

• Climate is important to plant, animal and human life. Plants and animals can live in certain climates. Some adopt in special ways. The needle shape leaves of conifers for example, help the trees adjust to cold climates. The short fur of desert animals helps them survive hot, dry climates. People also adjust what they wear, the kinds of home they build, and kinds of foods they grow.

Temperature

Precipitation

Air pressure

Wind

• Is the amount of heat found in the atmosphere.

*The heat in the atmosphere comes from the sun. Each day the small amount of the sun’s total energy reaches the top layers of the Earth’s atmosphere.

• Earth’s atmosphere acts like the glass roof of a greenhouse. In a greenhouse the sun’s rays pass through the glass windows and warm the plants.

INFRARED RADIATION are short waves that are reflected back into space that are change into longer heat waves.

GREENHOUSE EFFECT is the natural process by which the infrared radiation do not easily escape back through the atmosphere because gases in the lower atmosphere take in some of the heat energy and sent it back to warm the Earth.

• Is the moisture that falls from the atmosphere onto Earth’s surface.

* Moisture that reaches Earth’s surface can be RAIN, SNOW, SLEET or HAIL. Moisture can also appear in the air as water vapor and its amount depends on the temperature of the air.

• Warm air can hold more water than cold air. The temperature of the air also tells what kind of precipitation will fall.

Example: Rain generally fall during

warm weather.Snow falls during cold

weather.

• Is the force exerted by the weight of air above a particular location.

* The uneven heating of Earth’s surface by the sun leads indirectly to differences in air pressure.

• On Earth there are seven pressure zones, or areas with the same general air pressure. Two zones-those at each pole- are permanent. The other five are semi-permanent because the belts may move more north or south when season change.

*high pressure areas have clever skies and calm weather.

*low pressure areas have cloudy skies and stormy weather.

• Is the flow of gases on a large scale.

*When air moves from high pressure area to a low pressure area, it creates WIND. The greater the difference between the two areas, the faster the wind speed.

• PREVAILING WINDS- are wind patterns generally found in a place.

*DOLDRUMS (places near the Equator) is a calm region, it has little or no WIND.

TRADE WINDS are prevailing winds in LOW latitudes.

• PREVAILING WESTERLIES are winds blown from the west in middle latitudes.

• POLAR EASTLIES are winds from the east in high latitudes.

* JET STREAMS are strong belts of winds high up in the air, it flows from west to east. These streams are much like a very fast-moving, winding river. The jet streams change their positions in the atmosphere from day to day and season to season.

Temperature, moisture, air pressure, and wind work together to produce CLIMATE. The climate they make may be controlled by several things. Among these are:

* latitude* heating and cooling

differences of land or water

* prevailing wind patterns* altitude

• Latitude is the most important control on climate because it shows the angle at which the Sun’s rays hit Earth.

• Near the Equator these rays hit the surface of Earth more vertically or straighter than at other latitudes.

• Vertical rays cover a smaller surface area and give more energy for heat than indirect rays. For this reason, low-latitude areas near the Equator are nearly always warm for the whole year.

• Temperate areas- areas in the middle latitudes receive somewhat vertical rays part of the year and have temperatures that are neither too hot nor too cold.

* Areas in high latitudes never receive vertical rays and are cold all year.

• Seasons are the result of Earth’s tilt on it’s axis 23.5°; the fact that Earth revolves around the Sun and that the tilt of Earth on it’s axis remains parallel throughout it’s revolution.

• As a result different parts of Earth receive higher and lower levels of radiant energy at different times of the year creating the seasons

• Another important control on climate is brought about by the heating and cooling of land and water.

• The difference in the heating and cooling of land and water along coastline also create light winds.

Winds tends to blow in some directions more than others.

For example:

*In middle latitudes the prevailing westerlies blow from west to east. This is the reason why Places on western side of continents in the middle latitudes have much milder winters than places on eastern sides.

*Westerlies also affect summer climates. The reason for this is that the summer air is cooled by the water of the Pacific Ocean.

• Climate is the characteristic condition of the atmosphere in the lower layer of Earth’s atmosphere. It is based upon the long- term weather in an area accumulated over a period of at least 30 years.

• Two of the most important factors used in determining the climate of an area are the air temperature and the amount of precipitation received.

• The climate of a region will determine which types of plants will grow as well as what kind of animals will be there.

• The angle of the sun’s rays is most direct from 0° to 23.5° making that area the hottest. The angle of the sun’s rays are least direct from 66.5° to 90° making that the coldest area on Earth. In the middle are the more moderate temperatures which vary more with season.

• Trade winds are located in the tropical regions blowing from the northeast in the northern hemisphere and from the southeast in the southern hemisphere.

• The trade winds meet at the equator and rise as the air is heated. The rising air cools, forms clouds and creates precipitation. The bands of cloudy and rainy weather near the equator create what we know as normal tropical conditions.

• In the mid-latitudes (30°- 60°) the Westerlies steer the storms from west to east.

• Our climate is based upon the location of the hot and cold air masses as well as the atmospheric circulation caused by the Trade Winds and the Westerlies.

Climate Classification

• The Koeppen Climate Classification System is the most widely used for classifying the world’s climates.

• It was created by the Russian-German climatologist Wladimir Koeppen who divided Earth’s surface into climatic regions that matched the world patterns of vegetation and soils.

•Moist tropical Climates •Dry Climates•Humid/Middle Latitude Climates•Continental Climates•Cold Climates

• known for their high temperatures year round and for their large amount of rain year round.

• area of the world near the Equator between the Tropic of Cancer and Capricorn.

• characterized by little rain and a huge daily temperature range.

• Two sub-groups:semiarid or

steppe arid or desert

• Land and water differences play a large part

• These climates have warm, dry summers

and cool, wet winters

• can be found in the interior regions of large land masses

• total precipitation is not very high and seasonal temperatures

• These climates are found where permanent ice and tundra are always present

• Only four months of the year have above freezing temperatures

• The major climate groups show the dominance of special combinations of air mass source regions:

Low Latitude Climates Mid-latitude climates High latitude climates

Tropical Moist Climates – rainforest

Wet-Dry Tropical Climates – savanna

Dry tropical Climate – desert biome

Low latitude climates are controlled by equatorial tropical air masses.

Rainfall is heavy in all months. The total annual rainfall is often more than 250 cm (100 in). There are seasonal differences in monthly rainfall but temperatures of 27C (80 F) mostly stay the same. Humidity is between 77% and 88%. Summers are warm and very humid. It rains a lot in winter.

Latitude Range: 10 S to 25 NGlobal Position: Amazon Basin; Congo

Basin of Equatorial Africa; East Indies from Sumatra to New Guinea

Tropical Moist Climate- rainforest

A seasonal change occurs between wet tropical air masses and dry tropical air masses. As a result, there is a very wet season and a very dry season. Temperature ranges around 16C. The annual precipitation in all months is less than .25cm (.01 in).

Latitude Range: 15 to 25 N and S Global Position: India, Indochina, West

Africa, southern Africa, South America and the north coast of Australia

Wet-Dry Tropical Climates – savanna

These climates are found in low latitude deserts between 18 to 23 in both hemispheres centered on the tropics of Cancer and Capricorn. Winds are light allowing for the evaporation of moisture in the intense heat. Air sinks so the area is seldom penetrated by air masses that produce rain creating a very dry heat. The temperature ranges around 16 C.

Annual precipitation is less that 0.25cm (0.1 in).

Global Position: southwestern United States; northern Mexico; Argentina; north Africa; south Africa; central part of Australia

Climates in this zone are affected by the tropical air masses moving toward the poles and polar air masses moving toward the equator.

These two air masses are in constant conflict.

Either air mass may dominate the area for a time, but neither has exclusive control.

•This climate has a wet winter and an extremely dry summer. Plants have adapted to the extremes in rainfall and temperature during the summer and winter seasons. Plants range from forests, to woodland, to scrub. Temperature range is 7 C (12 F) with 42 cm (17 in) of precipitation.•Latitude Range: 30 - 50 north and south•Global Position: central and southern California; coastal zones bordering the Mediterranean sea; coastal western Australia and southern Australia; Chilean coast; Cape Town region of South Africa

•This is a semi-arid climate with less than 10 cm (4 in) annual precipitation in the driest regions to 50 cm (20 in) in the moister areas.

•Latitude Range: 35 - 55 N

•Global Position: Western North America (Great Basin, Columbia Plateau, Great Plains); Eurasian interior, from eastern Europe to the Gobi Desert and north China.

•This climate is the battleground of polar and tropical air masses. Seasonal changes between hot summers and cold winter are very large. Precipitation varies from 40 to 60 in per year. The average temperature is 31 C (56 F)

•Latitude Range: 30 - 55 north and south

•Global Position: eastern parts of the United States and southern Canada; northern China; Korea; Japan; central and eastern Europe.

Dry Mid-latitude Climate – steppe forest

•This is a semi-arid climate with less than 10 cm (4 in) annual precipitation in the driest regions to 50 cm (20 in) in the moister areas.

•Latitude Range: 35 - 55 N

•Global Position: Western North America (Great Basin, Columbia Plateau, Great Plains); Eurasian interior, from eastern Europe to the Gobi Desert and north China

High Latitude Climates are dominated by polar and arctic air masses.

Boreal forest Climate – taiga

Tundra Climate – tundra

Highland Climate – alpine

Polar Ice Cap – cold desert

High Latitude Climates

• Polar and arctic air masses dominate these regions. Canada and Siberia are two air-mass sources which fall into this group.

• There is no counterpart in the southern hemisphere since the largest land masses are in the northern hemisphere.

Boreal forest Climate – taiga

•This is a continental climate with long, very cold winters and short cool summers. The temperature range is the greatest from -25º C (-14º F) to 16º C (60 º F) with the annual precipitation at 31cm (12 in).

•Latitude Range: 50º - 70º north and south

•Global Position: central and western Alaska; Canada from the Yukon to Labrador; Eurasia, from northern Europe across all of Siberia to the Pacific Ocean

•This climate is found along arctic coastal areas. The arctic air masses dominate the area but ocean winds keep temperatures from being as severe as interior regions. The winter is long and severe. There is a short mild season but not a true summer. Temperatures range from -22º C to 6º C (-10º - 41º F). Average precipitation is 20 cm (8 in).

•Latitude Range: 60º - 75º N

•Global Position: arctic zone of North America; Hudson Bay Region; Greenland coast; northern Siberia bordering the Arctic Ocean.

•Highland climates are cool to cold found on mountains and high plateaus. The temperature cools rapidly as the altitude gets higher. These climates are very important to mid latitude climates since they are a storage area for water in the form of snow which melts in the spring. Temperatures range from -18º -10º C (-2º - 50º F) and precipitation average 23 cm (9 in).

•Latitude Range: All over the world.

•Global Position: Rocky Mountain Range in North America; the Andean mountain range in South America; the Alps in Europe; Mt. Kilimanjaro in Africa; the Himalayans in Tibet; Mt. Fuji, Japan.

•This region is permanently frozen with no temperatures above 32º F. Precipitation is very low but varies from region to region.

•Latitude Range: 60º - 90º N and S

•Location: Arctic; Antarctica; Greenland.

It is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years.It may be a change in average weather conditions or the distribution of events around the average . it maybe limited to a specific region or may occur across the whole earth. it affects more than just a change in the weather , it refers to seasonal changes over a long period of time.

• If the heat from the sun cannot escape through the earth’s atmosphere then the ice at the north and south poles could melt.

• This could have a huge effect on the low lying areas of the world.

The effect of a Rise in Sea Level on the Nile Delta

• We could see a change in the boundaries between grassland, forest and shrub lands.

• This change in vegetation zones could cause famine in arid areas such as Africa that depends on a certain type of crop.

• It could also cause mass movement of people away from arid regions. And this could cause huge over-crowding in towns and cities.

• The range of pest could change if the vegetation

changed.. This could bring about an increase in

disease levels.

• Scientist believe that if the temperature increased by 3-5 degrees Celsius, the

number of people potentially exposed to malaria(caught from

mosquito) could increase from 45%-60% of the worlds

population.

The Malaria Carrying Mosquito

It could be affected by a change in temperature.It has been predicted that an increase in temperature would affect species composition.Scientist believed that up to two thirds of world’s forest would undergo major changes. They also believed that desserts would become hotter, and desertification would extend and become harder to reverse.

The sea affects the climate of a place. Coastal areas are cooler and wetter than inland areas. Clouds form when warm air from inland areas meets cool air from the sea. The centre of continents are subject to a large range of temperatures. In the summer, temperatures can be VERY hot and dry as moisture from the sea evaporates before it reaches the centre of the continent.

• Ocean currents can increase or reduce temperatures.

• E.g. The main ocean current that affects the UK is the Gulf Stream.

the Gulf Stream is a warm ocean current in the North Atlantic flowing from the Mexico, Northeast along the U.S coast, and from there to the British Isles.

The Gulf of Mexico has higher air temperatures than Britain as it’s closer to the equator. This means that the air coming from the Gulf of Mexico to Britain is also warm. However, the air is also quite moist as it travels over the Atlantic ocean. This one reason why Britain often receives wet weather.

The Gulf Stream keeps the west coast of Europe free from ice in the winter and, in the summer warmer than other places of similar latitude.

Winds that blow from the sea often bring rain to the coast and dry weather to inland areas. Winds that blown to Britain from warm inland areas such as Africa will be warm and dry. Winds that blow to Britain from inland areas such as the Netherlands will be cold and dry in winter. Britain prevailing winds come from a south westerly direction over the Atlantic. The winds are cool in the summer and mild in the winter.

Mountains receive more rainfall than low lying areas because the temperature on top of mountains is lower than the temperature at sea level. That is why you often see snow on the top of mountains all year round. The higher the place is above sea level the colder it will be. This happens because as thee altitude increases, air becomes thinner and is less able to absorb and retain heat.

• The proximity to the equator affects the climate of a place.

• The equator receives the more sunlight than anywhere else on earth. This is due to its position in relation to the sun.

• Which affects wind and rainfall patterns, has been blamed for droughts and floods in countries around the Pacific Rim.

• Refers to the irregular warming of surface water in the pacific.

• The warmer water pumps energy and moisture into the atmosphere, altering global wind and rainfall patterns.

• The phenomenon has caused tornadoes in Florida, smog in Indonesia, and forest fires in Brazil.

• We humans, have been affecting the climate since we appeared on this earth million of years ago. In those times, the affect on the climate was small.

• Trees were cut down to provide wood for fires. Trees take in carbon dioxide and produce oxygen. A reduction in trees therefore have increased the amount of carbon dioxide in that atmosphere.